Skinning machine having automatic blade pitch control



y 1966 D. L. RUNNELLS, JR., ETAL 3,249,139

SKINNING MACHINE HAVING AUTOMATIC BLADE PITCH CONTROL Filed Nov. 13,1962 3 Sheets-Sheet 1 mn/e/vrops DAV/0 L. RUNNELLQJI'. d'ROME K. LAMPER055??- u. 5205/93/44 BY l/ohw A. HARRINGTON we 70A w. mm use May 3,1966 D. L. RUNNELLS, JR.. ETAL 3,249,139

SKINNING MACHINE HAVING AUTOMATIC BLADE PITCH CONTROL Filed Nov. 15,1962 5 Sheets-Sheet 2 May 3, 1966 D. L. RUNNELLS, JR.. ETAL 3,

SKINNING MACHINE HAVING AUTOMATIC BLADE PITCH CONTROL Filed Nov. 13,1962 3 Sheets-Sheet 5 lA/VENOIQS DAV/0 L RUNNELLS, J d'ROM K. LAMP!ROBfRT d. BRORSMA JOHN A. HARE/N670 BY were? 01/. KRAUSE ZZMZW/ATTORNEYS United States Patent 3,249,139 SKINNIN G MACHINE HAVINGAUTOMATIC BLADE PITCH CONTROL David L. Runnells, Jr., Grand Rapids,Jerome K. Lampe, Grand Haven, Robert J. Broersma, Spring Lake, John A.Harrington, Grand Rapids, and Victor W. Krause, Rockford, Mich.,assignors to Wolverine Shoe & Tanning Corporation, Rockford, MiClL, acorporation of Michigan Filed Nov. 13, 1962, Ser. No. 236,862

12 Claims. (Cl. 146-130) This invention relates to skinning machines,and more particularly to an improved skinning apparatus capable ofseparating residual meat and fat from the entire saddle portion of hogskins.

Hog skins, when properly treated, provide excellent material for shoes,purses, belts and a variety of other goods. Conventional hog butcheringmethods include as an initial step the sawing of the hog carcass throughthe backbone to form two equal halves or hog sides. After the main meatand bone portions are removed from the hog sides, the residual meat andfatforming bacon and similar valuable products are sliced from the skinduring what is commonly termed the skinning process. This leaves tworelatively small segments of hog side skin useful for theabove-mentioned leather goods. .Since the hog skin is split when thecarcass is split, the two small pieces resulting involve wasted materialat the edge portions when a useful piece of leather is cut out fromeach.

Present hog skinning devices, although very useful, have somelimitations in not providing sufficient sensitivity or control ofcutting depth of the meat from the skin. The skin is relatively thinadjacent the belly, but gradually changes to a thickness at the rib cagearea of about double the belly area thickness. Also, the fat backportion of a chilled hog side is stiffer in its slightly curved orarcuate shape than the belly areas. More pressure is therefore necessaryto flatten the fat back for proper cutting as it passes the knife.Consequently, conventional pressure elements applying a generallyuniform pressure against the fat back and the belly areas do not elfectoptimum results. Moreover, the skinning knife edge does not provideoptimum skinning on these areas. The pressure and blade depth must becompromised between the belly and fat back areas. Too much pressureapplied to the belly area as it is pulled past the knife causesstretching of the skin. Too little pressure on the fat back preventscutting to the optimum depth. If the knife is pre-set to accommodate thethick skin, meat and fat are left on the thin skin. If the knife ispre-set to accommodate the thin skin, tough skin :or rind is left on themeat.

Another limitation of present skinning apparatuses is the tendency for afibrous sheath to form on the cutting blade edge, and thereby limit theaccuracy of skinning.

When effecting this skinning action by pulling the skin past the bladeedge, gripper means must also be utilized. In prior structures, there isrequired either skin-penetrating gripping means which damages the skinedge, or air cylinder operated clamping means which grasps a fat wedgeas well as the skin. This clinging fat wedge impedes the fleshingoperation on the skin. Further, and probably more important, after theskinning operation on conventional equipment, the skin is not orientedfor the next operation and is at a low position near the floor. It must,therefore, be lifted to an elevated position and reoriented for the nextoperation.

Another disadvantage of present equipment is the ineffectiveness inskinning hot carcasses, ie those skinned within about 2545 minutes afterdeath. These hot carcasses are still pliable and require no pressurerollers for skinning. However, a hot carcass can conceivably causecontamination of the skinning blade to thus affect subsequently skinnedcarcasses. Further, fibrous tissues tend to collect on the blade edge tolower the quality of the skinning.

It is therefore an object of this invention to provide a skinningapparatus that leaves the skin oriented in an elevated position readyfor the next operation. The skin moreover has no fat wedge to beremoved.

It is another object of this invention to provide a skinning apparatusthat enables skinning of complete-saddle portions of hog skins in anaccurately controlled manner. It provides exact and variable cuttingdepth of the meat from the skin, both in the thin-skin, softer bellyareas on opposite sides of the complete skin and in the thick-skin,harder fat back areas in the center of the skin. This control isachieved even though first one belly portion is skinned, then a fat backportion, and then another belly portion is skinned. This exact depthcontrol is achieved even though the skin is chilled, rather stiff, andsomewhat arcuate in configuration, so that the stiffer fat back areas donot flatten out as readily as the softer belly areas. It enables moreeffective use of the skin since one large piece is achieved, rather thantwo small pieces.

It is another object of this invention to provide a skinning apparatuswherein every bit of meat, as well as skin, is useful and undamaged,including the edges where gripping occurs.

It is another object of this invention to provide a skinning apparatuscapable of continued high skinning speeds and high quality control dueto a novel cutting action. The knife edge is generally free frombuild-up of a fibrous sheat to impede skinning.

It is still another object of this invention to provide a skinningapparatus having unique knife blade control effecting a variable pitchcutting effect. Moreover, the pitch can be automatically controlled inresponse to an independent parameter, preferably skin movement past theknife edge, to provide optimum blade pitch and cutting action both inthe soft belly areas and in the harder fat back areas. This is achievedeven though the blade pitch must vary first to accommodate the softareas, then the hard areas, and then the soft areas again. This isachieved on a programmed basis. 4

It is another object of this invention to provide a skinning apparatuswherein the pressure contacting means holding the skinand meat againstthe cutting blade is controllably variable in pressure applied.Moreover, the pressure intensity is automatically controlled in responseto an independent parameter, preferably skin movement. This is effectedsimultaneously with the automatic blade pitch control, and on aprogrammed basis.

Another object of this invention is to provide a skinning apparatusenabling skinning of hot carcasses without danger of contamination fromone skin to another, and without build-up of a fibrous sheath on theblade edge.

A further object is to provide a unique edge pre-cutter means and methodenabling gripper means to grasp only skin. No fat or meat wedge isgrasped. The skin is not punctured. All of the fat and meat portions aretherefore saved and useable. A novel gripping means is provided to graspthe skin for pulling it past the knife.

It is another object to provide a machine capable of pulling a skin froma conveyor at a convenient height, and after skinning is complete, ofplacing the skin and separated meat back on the conveyor automatically,thus saving the manual labor ordinarily required to remove the skin andmeat and place the-m on the conveyor.

It is still a further object to provide a skinning machine tat placesthe tissue to be severed in a state of high ,ress to provide optimumcutting efiiciency and subvantially reducing drag of the skin on theknife.

These and several other objects of this invention will ecome apparentupon studying the following specificaon in conjunction with the drawingsin which: FIG. 1 is a perspective view of the complete skinningpparatus;

FIG. 2 is a perspective view of the edge pre-cutting leans;

FIG. 3 is an elevational sectional enlarged view taken [1 plane IHIII ofFIG. 1 and showing the skinning rocess;

FIG. 4 is an elevational view of the variable pressure antacting meansand the variable pitch cutting means 'ith one type of control meanstherefor;

FIG. 5 is a perspective enlarged view of the cutting nife and holder;

FIG. 6 is a fragmentary perspective enlarged view of re front of thecutting means;

FIG. 7 is a fragmentary sectional view showing the itting operation ofsoft fatty areas;

FIG. 8 is a fragmentary. sectional view lttin'g operation of meatyareas;

FIG. 9 is a fragmentary perspective view of the upper de of the skinsupport means and the gripper means IOWII open and shifted;

FIG. 10 is a fragmentary view of a portion of the re-cutter; and

FIG. 11 is a partial schematic view of the apparatus, lowing the basicinterrelationship of the cylinders with re control system.

Basically, the inventive skinning apparatus comprises bster clawgripping means to grip and shift the comined skin and attached meat andfat past a cutter blade, ariable pitch blade means shiftable on aprogrammed asis to provide controlled pitch changeable in responsemovement of the skin, and a variable pressure contactlg means holdingthe skin and meat to the blade and ariable on a programmed basis toprovide a controlled ressure change in response to movement of the skin.It iereby cooperates with the variable pitch blade to elfect )ntrolleddepth cutting of the meat in both soft belly em and in harder fat backareas. The blade pitch 1d the pressure application variation ispreferably ef- :cted through fluid cylinders operated by a meansconolled in response to skin movement. The skinning :curs by pullingskin and meat around the edge of a ainnin g bar, while the blade isoscillated laterally to rovide a unique, fast cutting action.

A novel pre cutter slices the side edge of the skin cm the meat beforeit is gripped, to thereby prevent amage to the meat edge by providing aflap of skin to e grasped.

The skinning apparatus includes hot-water cleansing leans, preferably inthe blade itself, to clean the blade Eter each skin. This enablesskinning of hot carcass tddle portions without contamination. Also, thehot ashin g spray removes fibrous tissues and lubricates the lade edge.

Referring to the drawings, the novel skinning apparatus is shown asincluding the novel pre-cutter means 12, support means 14, the variablepitch cutting blade leans 16, the variable pressure contacting means 18,1d the skin support means 20. The novel skin gripping leans 2-2 and itsfluid cylinder actuators 24 as well as :inning bar 26 are shown morespecifically in FIG. 3.

The novel skinning apparatus is mounted upon iitable legs 28. Thepre-cutter device is shown mounted pon other suitable legs 30. Theskinning device is IOWH mounted between a pair of side panel members 2and 34 which include upstanding ears 36 and 38 to lpport the variablepressure contacting means 18. Basic showing the movement of the whole orcomplete hog skin and meat is to the left from the'pre-cutter support 14as viewed in FIG. 1, and then downwardly around the skinning bar 26 asillustrated in FIG. 3.

The pre-cutter device 12 preferably comprises a round rotatable cuttingblade or disc 40 operated by motor 4 2, which may be an electricalmotor, an air motor, or other similar device. The pre-cutter support 14includes a series of conveyor rollers mounted between side flanges sothat the skin will readily glide over the rollers and past thepre-cutter in the direction of the arrow illustrated in FIG. 1. A guideflange v44- adjacent the preecutter 40 limits the depth of thepre-cutting action illustrated specificially in FIG. 2. The pre-cutteris preferably mounted adjacent the skinning apparatus for maximumcooperation therewith. However, in the broadest aspects of thisinvention, it should be realized that the pro-cutting means may assumeseveral different structural make-ups and may be mounted completelyindependently of the main skinning apparatus.

For illustrative purposes, a complete hog skin with integral meat andfatty areas 5'2 is shown in FIG. 2. Although shown to be substantiallyflat, it should be realized that the combination often is usuallysomewhat arcuate in configuration. The central fat back portion isusually more rigid than the softer belly areas 56 and 56 where the skinis longitudinally slit. The fat back includes lean areas 54. A phantomline 58 on the skin in FIG. 2 illustrates where conventional butcheringtechniques normally cut the skin into two like parts. According to thenovel method of handling it, the skin is preferably kept whole.

The pre-cutter blade 40 whirls to sever an edge of skin 50 from meat 5-2to a depth of up to a couple of inches in width. This severed skin flapis then depressed by plow edge 60 (FIG. 10) of support 14 so that theskin passes through slot 62 (FIG. 1) in side panel 34, to a positionbetween the jaws or lobster claws 64 and 66 of the novel gripper means22.. These claws are preferably corrugated on their inner surfaces toefiect a secure gripping action on the skin. Since only the skin isgripped,-the complete meat portion, is left for valuable edibleproducts. As seen in FIG. 3, gripper means 22 is located beneath supportmeans 20.: This support 20 is essentially a tilted platform means whichincludes bar guide 26 at the lower end and a series of rollers 70parallel to skinning bar .26 and extending diagonally upwardly and awayfrom skinning bar 26. The bar assumes only a small vertical space ascontrasted with the drum mechanism of prior devices. The tiltedplatform, in combination with this relatively small bar, enables theskin to be in an elevated position after the skinning operation hasoccurred.

The jaws of the gripper means may be operated by a pair of fluidcylinders 72 and72'is-hown more specifically in FIG. 9. These air orhydraulic cylinders 72 are pivotally mounted to a transverse supportbeam 80, the ends of which are 'affixed to a pair of-block riders 86 and88 on opposite sides of the apparatus. These riders slide on a pair oflongitudinal pilot bars 90 and 92 ('FIG. 9) secured between mountingplates 94 and 96 at the base of the apparatus (FIG. 1) and a cross panel98 at the upper end of the apparatus.

The skinning guide bar 26 is here shown in the form of an elongatedelement having an oblong cross section. On-the other hand it may be acylindrical bar similar to rollers 70. Mounted adjacent the lower edgeof guide bar 2 6 and at a controlled spaced relationship thereto is thecutter blade means 16. This includes a blade element 100, and a bladeholder including parts 102 and 104. The blade preferably has a generallyT-shaped configuration including cross element to retain it in theholder. The blade holder is in turn pivotally mounted to support 106 bybracket 107. Supmove the blade in an arcuate path to vary the pitchangle of the blade with respect to skinning bar 26. This variation is tosuit the varying characteristics of the tissue fibers across the skin.Also, the depth of cut can 'be controlled by extension and contractionof a second fluid cylinder 121 aflixed to the frame portion 123 andhaving its rod 125 pivotally attached to blade holder 102 to vary thespacing between the blade edge and the skinning bar 26. This supportstructure may vary widely as long as the pitch variation and depthvariation is achieved. The fluid cylinder 1 18 is aflixed beneathplatform 1 20. The blade 100 is thus mounted for pivotal arcuatemovement to change its pitch, i.e. cutting angle with respect to bar 26,and change the depth of cut to enable accommodation of both soft,thin-skin, belly areas and tougher, thickskin back areas.

The blade 100 is laterally sliable a limited amount within its holder,so that it may be oscillated laterally by a conventional fluid motor142. This motor is shown mounted to the back of the-blade holder, andhaving a portion 144 extending through slot 146 in holder portion 104and afiixed to blade 100 (FIG. 5). The motor may be mounted in othersuitable ways, e.g. at the end of the blade holder.

The blade holder also preferably includes a series of cleaning, hotwater spray outlets 150 ('FIG. 6) adjacent the blade edge. Pressurizedwater at a temperature of at least 126 F. may be injected through tube156 (FIG. 5) into passageway 158 (FIG. 6) extending longitudinally ofholder portion 102, through spaced passageways 1 60, and to outlet ports150 to periodically spray and clean the blade edge. This enables hotcarcass skinning without danger of contamination from one skin toanother, since the blade can be sprayed clean after each skin. The wateralso serves as a lubricant. It further removes fibrous tissue caught onthe blade edge, thereby helping to assure neat accurate cutting.

Blade holding portions 102 and 104 are also preferably scalloped as at162 along their leading edge to reduce frictional contact with the bladeduring its oscillatory action.

Mounted between upwardly extending panel ears 36 and 38 of the frame isa pressure application means '18. This preferably comprises a pluralityof rollers 180, each mounted on a suitable U-shaped bracket 182. Eachbracket is mounted to' a common transverse support bar 184 by a pair ofstuds 186 having compression springs 185 between the roller and bar(FIG. 1). Thus the rollers have limited resiline-t movement towardsupport bar 184 when pressure is applied to the combination skin andmeat. Support bar 184 is mounted between a pair of rollers 190 which arevertically reciprocable in channel guides 192. Movement of the assemblyis achieved through a respective pair of fluid cylinders 194 and 196affixed to frame portions 36 and 38. Thus by reciprocation of thepistons and piston rods of these air cylinders, the pressure of rollers180 on the combined skin and adjacent fat and meaty areas against theblade may be closely varied in an accurately controlled manner. Bvcontrollably varying the roller pressure, optimum pressure can beapplied both to the belly area to flatten it without skin stretching,and to the tougher flat back to completely flatten it. These factorshold true for con ventional chilled carcass skinning. When skinning hotcarcass products, pressure rollers are not normally required sincetheskin and meat are soft and pliable.

The pitch of knife blade 100 and the pressure applied by contact means18 is controlled on a programmed basis to provide optimum controlleddepth to the cut as the chilled skin pases the cutter blade around guide26, including the initially cut belly area 56 where soft tissue and thinskin predominate, the central fat back area where tougher tissue andthick skin predominate, and the opposite belly side area 56'.

Referring to FIG. 4, one suitable programming control means isillustrated. The programmed basis is controlled in response to anindependent parameter i.e. movement of the skin and gripper means.Before the stroke of air cylinders 24 begin to shift the blocks 86 and88 (FIG. 9), gripper means 22 and skin 50 upwardly and to the right inthe apparatus as illustrated, block 86 is in the position shown in solidlines in FIG. 4. The control means is shown to include a plurality oflimit switches 200, 202, 204 and 206 actuated by block 86. These limitswitches are electrically connected 'to solenoid valves 300, 302, 304,306 through the electric lines shown without arrows in FIG. 10, with thecompressed air being supplied to the valves and then to the cylinders asshown by the arrows in FIG. 10. With controlled shifting of the valvesfrom one position to another, the reguated air flow is caused tovariably control fluid pressure to (1) fluid cylinders 24 shifting thegripper means and skin, (2) fluid cylinders 194 and 196 operating thepressure rollers, (3) fluid cylinder 1'18 shifting the pitch of knife100, and (4) fluid cylinder 121 to vary the depth of cut of knife 100.At the start of the operation, the roller assembly 18 is preferablypivoted on rod 184 to the position shown in phantom in FIG. 4 to allowentry of the skin and meat therebeneath. Then the roller assembly ispivoted down so that the apparatus is in the position shown in solidlines in FIG. 4. At this position, a minimum of pressure is applied bycylinders 194 and 196 to roller assembly 18 so that the applied rollerpressure to the product will be about 40 p.s.i. for example. Alsocylinder 118 is retracted to the lowermost position to have the smallestangle between the knife, i.e. holder and the lower surface of thecombined means and skin on the support "20. Also cylinder 121 isretracted to move the knife to its closest spacing from bar 26 to givethe thinnest skin cut. The pressure applied to cylinders 24 will besmall to cause slow movement of the gripper and skin.

Actuation of limit switch 202 by block 86 will shift the solenoid valvesto increase pressure to cylinders 194 and 196, to speed up movement ofcylinders 24, to shift cylinder 118 to increase the blade pitch, and toshift cylinder 121 to take a thicker skin cut. Actuation of. limitswitch 204 will result in the maximum pressure to cylinders 194 and 196for maximum roller pressure. It will cause a lesser pressure tocylinders 24 to obtain a slow skin speed.

Maximum pressure to cylinder 118 Will cause maximum blade pitch. Limitswitch 206, when actuated, shifts the valves to decrease the fluidpressure to the cylinders to a moderate value of about the same value aswhen switch 202 is actuated. Thus as soft belly tissue in portion 56 ofthe hide (FIG. 2) is drawn past the knife blade, the blade Will have apitch such as that illustrated in FIG. 7 since the fat readily cuts asdeep as necessary at this angle. At first the skin movement is slow andthen speeds up. As movement of the skin continues into the tougher fatback areas, the angle and pitch of the blade changes so that it can cutto the proper depth even though the skin is thicker and more diflicultto flatten by the pressure rollers. The speed of skin movement decreasesin this tougher area. Simultaneously, the pressure on the rollers beginsin relatively small amounts since the soft belly portion is readilyflattened. As air cylinders 24 shift, however, the tougher, fat backarea 58 begins passing the knife blade 100. The roller pressure istherefore gradually increased. It is decreased again in the softopposite belly area 56.

Obviously, other forms of hydraulic, mechanical or electrical controlmeans to vary the pressure on the rollers,

1e blade pitch, and the skin speed in response to an inependentparameter, and thus accommodate the vary- 1g characteristics of the meatand skin can be utilized.

Operation To obtain a whole saddle portion of the skin, the back onemust be chisel split as with a pneumatic chisel to revent slitting ofthe adjacent skin. Then the major ieat and bone portions are cut out. Toremove the reiaining meat and fat from the whole hog skin saddle porionsuch as that illustrated in FIG. 2, the skin is placed :ngthwise on thepre-cutting support 14 and conveyed adicent guide 44 into revolvingcutter disc 40. This preuts a slit a couple inches wide between thebelly meat nd adjacent skin to form a flap. Plow bends the ap downwardlyto a position between the corrugated )bster claws 64 and 66 of the novelgripper mechanism 2. The skin now rests upon the top of tilted support20.

iext, the pair of air cylinders 72 and 72' are actuated to lose jaw 64against jaw 66 on the elongated narrow flap f skin. The gripper Z2 isthen ready to be shifted to ac right and diagonally upwardly along withthe pilot locks 86 or their equivalent on-guides 90 and 92. Rollerssembly 18 is then pivoted downwardly as in FIG. 4. With actuation oflimit switch 200, pressure applied to ollers 180 by fluid cylinders 194and 196 is at a minimum, lade is at its smallest angle with respect tothe bot- )m of the skin and meat as illustrated in FIG. 7 since 1e softbelly areas 56 are the first to be cut, the blade close to bar 26 sincethe belly skin is thin, and the ctuating pressure for cylinders 24 isvery small to start 1e skin at a slow speed. Fluid cylinders 24 areactuated shift the mechanism upwardly and to the right as illusrated topull the skin gradually around the front edge f guide bar 26 anddiagonally upward under the support latform 20. At the start, typicalvalues are 0-3 p.s.i. oller pressure and 300 inches per minute skinspeed...

During cutting, air motor 142 oscillates blade 100 With- 1 its holder toprovide a lateral cutting action. The griper means and skin are drawn inone general direction up uides 90 and 92 in a generally rectilinear,fashion. Aliough the chilled skin and meat are somewhat arcuate 1configuration, the pressure and blade angle minimize :tis'by pressingthe skin and meat properly into the blade. t8 the skin continues to moveand limit switch 202 is ctuated, the skin speed is accelerated throughthe soft elly tissue, e.g. to a velocity of about 1500 inches periinute. Further movement of the skin moves the tough at back portioninto the blade. Limit switch 204 is here ctuated. This slows the skinspeed to a medium speed of bout 1000 inches per minute for example bylessening re actuating fluid pressure to cylinders 24. Also the ollerpressure is increased to a maximum of about 30 .s.i., for example toflatten the tough fat back, the blade itch is increased to accommodatethe thicker skin in the th cage area, and the blade edge is shifted awayfrom ar 26 to accommodate the thick skin. After the fat back as passedthe blade, and the opposite belly portion 56' beginning to pass theblade, limit switch 206 is actuted to increase the skin speed again toabout 1500 inches er minute, decrease the roller pressure to a minimum,nd lessen the blade pitch and cut depth to accommodate 1e thin softskin. Instead of thefew exemplary limit witches shown, a large numbermay be mounted side by ide to provide a more gradual change ofconditions of 1ese three elements.

By so doing, completely programmed, controlled skining is achieved, inspite of the fact that thick, tough, firous, fat back areas areencountered in the center, soft 1in belly tissues are encountered onboth sides of the kin, and all variations are in between. All areexactly ut at to an optimum controlled depth.

When the mechanism has moved to the position illus- 'ated in'phantom onthe far' side shown in FIG. 4, the ripping jaws open as illustrated inFIG. 9 to automatically drop the elevated hog skin directly onto anotherconveyor means 91 for the next operation without requiring manualhandling. The meat, in the meanwhile, has automatically been carried offon conveyor means 93' (FIG. 4) to be used for valuable bacon and relatedproducts.

Not only can the novel device accommodate whole hog skins with acontrolled cutting depth to provide a larger 1 skin which can be used ina more efiicient manner, but

it also does not Waste meat along the edge of the skin where thegripping occurs. After the skin is dropped, hot water is sprayed fromoutlets onto the blade edge to cleanse it from any infectious substancepossibly encountered, and to remove fibrous tissues on the blade edge.This cleansing enables skinning of hot carcass skins, especially whenused in combination with the vibrating knife. In this case, pressurerollers are not normally required since the skin is soft and pliable. Inbrief, therefore, the inventive apparatus provides more leather, moremeat, faster production, less blade wear, less labor, and moreeconomical operation. Other advantages will be apparent to those skilledin the artupon studying the foregoing form of the invention asillustrated. Further, various obvious modifications in the severalfeatures of the inventive apparatus may occur to those in the art tosuit a particular situation, once the principles explained above areunderstood. These obvious modifications are deemed to be part of thisinvention, which is to be limited only by the scope of the appendedclaims and the reasonably equivalent structures to those definedtherein.

We claim:

1. A skinning apparatus for slicing meat from an animal skin comprising:means to secure and pull the combined skin and meat; a cutting blademounted to slice said meat from said skin during the pulling action;means mounting-said blade to allow arcuate blade movement to vary itspitch and to allow blade movement toward its edge to vary depth ofcutting and shiftable control means operably associated with said bladeand responsive to movement of said skin to vary the pitch of said bladein accordance with toughness characteristics of said skin and meat, andto vary the'cutting depth of said blade in accordance with skinthickness.

2. A skinning apparatus adapted to slice the meat and fat from the wholesaddle portion of a hog skin comprising: skin support means; means topull the combined skin and meat; cutting .blademeans to sever said skinfrom said meat as it is pulled along said support means; means mountingsaid blade means to allow blade movement to vary its cutting action;blade shifting control means operably associated with saidblade meansand positioned adjacent said support means and responsive with movementof a skin along said support means tosh-ift said blade means on aprogrammed basis over the width of said skin to effect controlled depthcutting in soft thinskin belly areas and in harder thick-skin fat backareas.

3. A skinning apparatus adapted to slice the meat from the whole saddleportion of a hog skin comprising: skin support means; means to pull thecombined skin and meat; cutting blade means to cut said meat from saidskin as it is pulled along said support means; pressure roller means forforcing said skin and meat into-contact with said knife; means mountingsaid pressure roller means, control means operably associated with saidmounting means to vary the pressure applied thereby on a programmedbasis over the width of said skin, said control means being responsivewith skin movement along said support means to provide cutting controlover fatty and meaty areas.

4. A skinning apparatus adapted to slice the chilled meat from the wholesaddle portion of a hog skin comprising: skin support means; means topull the combined skin and meat; cutting blade means to sever said meatfrom said skin as it is pulled; means mounting said blade means andallowing it to shift and vary the pitch thereof on a programmed basisover the width of said skin to effect controlled depth cutting in softareas with thin skin and harder areas with thick skin; pressure rollermeans for forcing said skin and meat into contact with said knife; meansmounting said pressure roller means to enable it to vary the pressureapplied thereby on a programmed basis over the width of said skin toflatten said skin and provide accurate cutting control over all areas;

blade shifting means; pressure roller shifting means; and control meansoperably associated with said blade shifting means and said pressureroller shifting means and responsive with movement of a skin along saidskin support means to achieve the programmed actions.

5. A skinning apparatus comprising: a tilted skin support means; a barsurface across the lower end of said support means; a knife blademounted adjacent said bar surface; and gripping and pulling meansmounted beneath said support means at an acute angle from said skinsupport means, to draw a skin through an obtuse angle from said supportmeans, and said gripping and pulling means being shiftable from aposition adjacent said bar surface, diagonally upwardly along theunderside of said tilted support to an elevated position, whereby .ananimal skin having meat thereon can be pulled from a position on saidsupport, past said blade to separate the meat and skin, around said barsurface, and diagonally upwardly to an elevated position for the nextoperation; conveyor means to receive said skin; and conveyor means toreceive said meat.

6. A skinning apparatus comprising: gripping means to grip an animalskin having meat thereon; means to shift said gripping means to pullsaid skin; a bar guide mounted to support said skin and allow it to bepulled around a portion of its periphery; a knife blade adjacent to andspaced from said bar guide to peel the meat from said skin as it ispulled around the bar; said blade being mounted to have a variable pitchwith respect to said bar guide; pressure contacting roller meansadjacent said blade and said bar guide; said contacting means being ofvari able pressure intensity; fluid cylinder means adapted to move saidblade arcuately and vary the pitch thereof; fluid cylinder means adaptedto shift said pressure contacting means; and both said fluid cylindermeans being responsive to movement of said skin.

7. A skinning apparatus comprising: gripping means to grip an animalskin having meat thereon; means to shift said gripping means to pullsaid skin; a bar guide mounted to support said skin and allow it to bepulled around a portion of its periphery; a knife blade adjacent to andspaced from said bar guide to peel the meat from said skin as it ispulled around the bar; said blade being mounted to have a variable pitchand spacing with respect to said bar guide; pressure contacting meansadjacent said blade and said bar guide; said contacting means being ofvariable intensity; fluid cylinder means adapted to move said blade andvary the pitch thereof and to vary the spacing thereof; fluid cylindermeans adapted to shift said pressure contacting means; valve controlmeans for said cylinder means; valve control means to cause saidpressure contacting means to apply less pressure at the beginning, toincrease in pressure at the center area of said skin, and to decrease inpressure at the end; and said valve control means adapted to cause saidblade to vary in pitch and in spacing for cutting depth from thebeginning to the center area of said skin, and to change back again atthe end.

8. In a skinning apparatus comprising: gripping mean-s v to grip ananimal skin having meat thereon; means to shift cent said skin to seversaid meat from said skin when the combined skin and meat to a positionadjacent said gripping means; and an edge slicing knife mounted adjacentsaid means to sever the edge of said meat from the edge of said skin toallow a gripper to grasp only said skin.

9. In a skinning apparatus comprising: gripping means to grip an animalskin having meat thereon; means to shift said gripping means to pullsaid skin; cutter means adjasaid skin is pulled; means for guidingendwise movement of the combined skin and meat to a position adjacentsaid gripping means; an edge slicing knife mounted adjacent said meansto sever the edge of said meat from the edge of said skin and allow agripper to grasp only said skin; and a plow edge between said edgeslicing knife and said gripping means cooperable with the skin edge tobend it away from the severed meat and into said gripper means.

10. A skinning apparatus comprising: a cutting blade and guide means;variable speed pulling means to pull an animal skin and attached meatand fat past said blade; and control means operably associated with saidpulling means and responsive to skin movement, thereby controlling thespeed of said pulling means to suit the skin and meat characteristics.

11. A skinning apparatus comprising: a cutting blade and guide means;variable speed pulling means to pull an animal skin and attached meatand fat past said blade; said blade being variable; and control meansoperably associated with said pulling means and responsive to skinmovement thereby controlling the speed of said pulling means and thevariation of said blade to suit the skin and meat characteristics.

12. A skinning apparatus comprising: a cutting blade and guide means;variable speed pulling means to pull an animal skin and attached meatand fat past said blade; said blade being shiftable to have a variablepitch and cutting depth; shiftable pressure contacting means to flattenthe skin against said blade with variable pressure; and control meansresponsive to skin movement, and operably associated With said pullingmeans, blade, and pressure contacting means for controlling the speed ofsaid pulling means, the pitch and depth of said blade, and the pressureof said contacting means to suit the skin and meat characteristics.

References Cited by the Examiner UNITED STATES PATENTS 657,322 9/ 1900Taliaferro 146-130 1,172,058 2/1916 Scheyer 83-565 X 1,719,030 7/ 1929Smith 17-45 1,790,592 1/ 1931 Morrison 146-160 1,803,341 5/1931 Merrick146-1 30 1,837,514 12/1931 Agar 17-45 2,590,747 3/ 1952 Birdseye 146-1302,649,881 8/1953 Runnells et al 146-130 2,803,279 8/1957 Strand 146-732,912,027 11/1959 Townsend 146-130 3,010,352 11/1961 Dunlap 83-565 XLESTER M. SWINGLE, Primary Examiner.

LUCIE H. LAUDENSLAGER, J. SPENCER OVER- HOLSER, ROBERT C. RIORDON,Examiners.

1. A SKINNING APPARATUS FOR SLICING MEAT FROM AN ANIMAL SKIN COMPRISING:MEANS TO SECURE AND PULL THE COMBINED SKIN AND MEAT; A CUTTING BLADEMOUNTED TO SLICE SAID MEAT FROM SAID SKIN DURING THE PULLING ACTION;MEANS MOUNTING SAID BLADE TO ALLOW ARCUATE BLADE MOVEMENT TO VARY ITSPITCH AND TO ALLOW BLADE MOVEMENT TOWARD ITS EDGE TO VARY DEPTH OFCUTTING AND SHIFTABLE CONTROL MEANS OPERABLY ASSOCIATED WITH THE BLADEAND RESPONSIVE TO MOVEMENT OF SAID SKIN TO VARY THE PITCH OF SAID BLADEIN ACCORDANCE WITH TOUGHNESS CHARACTERISTICS OF SAID SKIN AND MEAT, ANDTO VARY THE CUTTING DEPTH OF SAID BLADE IN ACCORDANCE WITH SKINTHICKNESS.